The successful application of various in situ and ex situ analytical techniques has been demonstrated at the buried interface between a metal and an electrolyte. Scanning force microscopy (SFM), electrochemical quartz microbalance measurements (EQMB), grazing incidence x-ray di †ractometry (GIXD), Fourier transform infrared spectroscopy (FTIR) in the specular reÑection absorption mode and electrochemical charge measurements proved complementary in the characterization of a polycrystalline copper electrode in alkaline 0.1 M sulphate, perchlorate, Ñuoride and chloride electrolyte contact at pH 12. The surface exhibited a mixture of Cu(111) and Cu(200) grains of the order of 100 nm. Repeated potential scanning in the double layer and passive oxide region, between Ô1.4 and + 0.1 resulted in a complete reorganization of the surface morphology but no detectable corrosion. The V MSE , electrochemical exchange of and OH-between the electrolyte and the oxide Ðlm took place reversibly in H 2 O accordance with a solid-state growth mechanism. The copper atoms were redeposited at crystallographically preferred sites, generating comparatively homogeneously oriented, narrow Cu(111)-edged grain ridges of length ¿200 nm. In the Cu(I) potential range, the formation of several monolayers of amorphous could be conÐrmed. Cu 2 O Only after extended time periods in the Cu(II) oxide potential region, recrystallized to a (111) phase Cu 2 O accompanied by and In this region, one observed the formation of amorphous Cu 2 O(200) Cu 2 O(110). Cu(OH) 2 concurrent with further growth of Strong CuO-H IR stretching bands excluded the existence of CuO. At Cu 2 O. corrosive potentials of + 0.25 high anodic currents and substantial mass losses led to an electropolished V MSE , surface with isolated features of AE300 nm width and AE70 nm height.